As a protection device for reducing the impact to occupants when the automobile is subjected to a frontal collision, an airbag apparatus has been widely diffused. A conventional airbag apparatus is attached in a steering device or an instrument panel provided in front of an occupant. In the case of the conventional airbag apparatus, when the automobile is subjected to a frontal collision, the airbag is inflated at the front side of a driver seat and a front passenger seat to thereby restrain occupants sitting in the driver seat and the front passenger seat from moving to the front side. As a result, the occupants in the driver seat and the front passenger seat are effectively protected at the frontal collision of the automobile.
In recent years, protecting an occupant in an automobile at a side impact of the automobile also has been considered important. Thus, so-called side airbag apparatuses and curtain shield airbag apparatuses have been mounted in vehicles. Specifically, as shown in FIG. 8 for example, at the front passenger seat-side of an automobile 1, a curtain shield airbag apparatus 2 is provided so that an airbag is inflated at a position close to the inner side of the glass at the upper portion of a front door 1a. A side airbag apparatus 3 is provided so that an airbag is inflated at a position close to the inner side of the lower portion of the front door 1a. In FIG. 8, although the curtain shield airbag apparatus 2 and the side airbag apparatus 3 are shown only at the front passenger seat-side, the curtain shield airbag apparatus 2 and the side airbag apparatus 3 are also provided at the driver seat-side in an actual case.
When another vehicle 4 laterally collides with the automobile 1 as shown by the arrow X in FIG. 8, the curtain shield airbag apparatus 2 and the side airbag apparatus 3 are respectively inflated at a position close to the inner sides of the front door 1a, i.e., an outer region of the front passenger seat, to thereby protect the body of the occupant of the front passenger seat from having a direct contact with the front door 1a. 
On the other hand, Patent Document 1 discloses an airbag apparatus that is attached within the ceiling of a vehicle interior. At a frontal collision of an automobile, an airbag is inflated downwardly at the front side of the occupant.
Patent Document 2 discloses an airbag apparatus that is attached within the instrument panel in front of the front passenger seat for example. At a frontal collision of an automobile, an airbag body is inflated at the front side of the occupant of the front passenger seat and a panel member provided in the vicinity of the ceiling is turned in the lower direction to thereby regulate a part of the airbag body inflated to the inner side of the vehicle interior from moving to the rear side in the vicinity of the ceiling.
Patent Document 3 discloses an airbag apparatus that is attached in an instrument panel in front of the front passenger seat for example. At a frontal collision of the automobile, an airbag body is inflated at the front side of the occupant of the front passenger seat and a panel member attached in the vicinity of the ceiling is turned in the lower direction to thereby regulate the airbag body from moving to the rear side in the vicinity of the ceiling so as to prevent a part of the airbag body inflated to the inner side of the vehicle interior from expanding between the head of the occupant and the ceiling.
In recent years, in order to restrain, at aside collision, the body of an occupant sitting at a side opposite to the collision from moving to the collision side, a center airbag apparatus has been suggested in which an airbag is inflated between two seats (e.g., Patent Documents 4 and 5).    Patent Document 1: JP2000-185618A    Patent Document 2: JP2005-067272A    Patent Document 3: JP2005-145225A    Patent Document 4: JP2004-217109A    Patent Document 5: JP2006-299698A